Semiconductor slice cassette transport unit

ABSTRACT

A transport mechanism (40) for transporting a semiconductor slice cassette between a clean carrier (10) and a process machine comprises a housing (41) having a forward portion (42) positioned in the people-occupied area of the clean room and a rear portion (46) positioned in the process machine area aerodynamically isolated from people. A moveable glider plate (50) is adapted to receive the carrier (10) and is initially positioned in an aperture provided in the upper surface of forward portion (42). A gearing mechanism (54) is provided which cooperates with glider plate (50) to move the semiconductor slice cassettes mounted on the base of carrier (10) between forward portion (42) and rear portion (46). The semiconductor slices are shielded from particulate contamination as the semiconductor cassette is transported on glider plate (50) between forward portion (42) and rear portion (46) and for evacuating any particulate contamination generated within transport mechanism (40) to create a negative pressure therein relative to the people-occupied area and the process machine area.

TECHNICAL FIELD

This invention relates generally to transport devices and morespecifically to a transport mechanism for shielding semiconductor slicesfrom particulate contamination while transporting and storing thesemiconductor slices between a portable carrying unit and a processmachine.

BACKGROUND OF THE INVENTION

Integrated circuit fabrication begins with a thin slice of singlecrystal semiconductor, usually silicon, and employs a combination ofphysical and chemical processes to create the integrated circuitstructure. The fabrication process is very sensitive to particulatecontamination and airborne particulates must be minimimized during thefabrication sequence, as even very small particles on the wafer surfacemay cause device defects. A reduced particle fabrication ambience isnormally achieved by the use of vertical laminar-flow (VLF) clean rooms.Lint-free garments are normally worn by persons working within thoseclean rooms to minimize operator-borne particles.

Tests have shown, however, that clean rooms can only reduce airborneparticulate levels to approximately 10-20 particles per cubic foot inareas where people are working, though clean levels of less then oneparticle per cubic foot can be achieved in areas aerodynamicallyisolated from people. Thus, where particle contamination densities ofless than one particle per cubic foot are required, the semiconductorslices currently cannot be exposed to VLF air in a clean room occupiedby people.

Various techniques have been developed for aerodynamically isolatingselected portions of a clean room from people. One such techniqueinvolves the use of air-drops or panels dropped from the filter ceilingof the clean room to enclose a people-free area, such as a processmachine. Another technique uses a portable carrying apparatus, termed aclean carrier, for storing and transporting semiconductor slicecassettes within the people-occupied area of the clean room. Such acarrier is described in co-pending application Ser. No. 644,282, filedAug. 27, 1984 entitled SEMICONDUCTOR SLIDE CASSETTE CARRIER, and shieldsthe semiconductor slices from VLF air in the people-occupiedenvironment.

Previously, when it was desired to load a cassette of slices or theslices themselves into a machine, the loading operation was performed byhand. Thus even using a clean carrier in combination with air panels,the slices would nonetheless be exposed to particulate contaminationduring the loading process. A need has arisen therefore for a mechanismfor transporting the semiconductor slices from the clean carrier to aprocess machine without exposing the slices to the people-occupiedenvironment. The present invention is thus directed to a transport unitdesigned to be used in conjunction with the clean carrier of theco-pending patent application identified above to transport cassettesand slices between the clean carrier in the people-occupied area of theclean room and a process machine area aerodynamically isolated frompeople, without exposing the slices. to particulate contamination orintroducing particulate contamination to the process machine area.

SUMMARY OF THE INVENTION

The present invention disclosed and described herein comprises atransport mechanism for use in conjunction with a clean carriercontaining semiconductor slice cassettes. The transport mechanism isdesigned to transport cassettes and slices between the clean carrier inthe people-occupied area of a clean room and a process machine areaaerodynamically isolated from people, without exposing the slices toparticulate contamination or introducing particulate contamination tothe process machine area. The transport unit in conjunction with theclean carrier thus reduces particulate contamination to less than 0.05particles/cm².

The transport mechanism comprises a substantially rectangular housinghaving a forward portion positioned in the people-occupied area of theclean room and a rear portion positioned in the process machine area.The rear portion is isolated from the forward portion behind an air droppanel extending from the ceiling of the clean room. The transport unitis designed to accept a clean carrier containing semiconductor slicecassettes at the upper surface of the forward portion. The transportunit includes a moveable glider plate constructed to matingly engagewith the base of the clean carrier and thus lock the clean carrier inplace on the unit. When the transport mechanism is activated, the cleancarrier is opened by sealing the carrier cover onto the top surface ofthe forward portion of the unit. The glider plate, along with thesemiconductor slice cassettes, will drop away from the cover and betransported through the housing and be repositioned proximate the uppersurface of the rear portion. The semiconductor slices are thus movedinto position for loading the process machine. If desired, the processmay be reversed to reseal the cassettes and slices within the cleancarrier.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the invention can be had by referenceto the following detailed description taken in conjunction with theaccompanying Drawings in which:

FIG. 1 is a sectional view of the clean carrier which is used inconjunction with the transport mechanisms of the present invention;

FIG. 2 is a bottom view of the clean carrier of FIG. 1;

FIG. 3 is a perspective view of the transport mechanism of the presentinvention;

FIG. 4 is a sectional side view of the transport mechanism of FIG. 3;

FIG. 5 is a sectional front view of the transport mechanism;

FIG. 6 is a sectional front view of the drive belt assembly;

FIG. 7 illustrates a belt tensioning device for use with the beltassembly of FIG. 6;

FIG. 8 is a sectional view of the glider plate assembly; and

FIG. 9 illustrates the movement of the glider plate.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the Drawings, wherein like reference numerals designatelike or corresponding parts throughout, FIG. 1 shows a sectional view ofthe clean carrier which is used in conjunction with the transportmechanism of the present invention. As shown in FIG. 1, the carrier 10comprises a base 12, a pair of spring mounted cradles 14 mounted on base12 for each supporting a semiconductor slice cassette. Each slicecassette contains a plurality of semiconductor slices ready for furtherprocessing. A cover 16 is disposed on base 12 to provide a sealedvolume. A handle 18 is attached to a latch 20, which removably couplescover 16 onto base 12 and which is adapted to be received in a latchtube 24 mounted proximate the center of the base 12. As also shown inFIG. 1, carrier 10 includes a pair of high-efficiency particle filters26 mounted in apertures through base 12 beneath cradles 14.

FIG. 2 is a bottom view of base 12 of the carrier 10. As shown in FIG.2, guide slots 28 are provided at the forward edges and on both sides ofbase 12. Those slots are provided to matingly engage with cooperatingprotrusions located on the transport mechanism, as described hereinafterin greater detail. Orifice 30 is provided at the terminal end of latchtube 24 and extends to the exterior of base 12. Guide members 32 aredisposed on both sides of base 12 in order to properly position cover 16over base 12. Further details of the construction of carrier 10 are setforth in the above identified co-pending patent application Ser. No.644,282, the disclosure of which is incorporated herein by reference.

Referring now to FIG. 3, a perspective view of the transport mechanismof the present invention is shown. As shown in FIG. 3, the transportmechanism 40 comprises a substantially rectangular hosing 41 having aforward portion 42 positioned in the people-occupied area of the cleanroom which is an area of relatively high contamination and a rearportion 46 positioned in the process machine area which is in area ofrelatively low contamination. The process machine area isaerodynamically isolated from people behind an air drop panel 49extending from near the filter ceiling of the clean room to near theflow of the room. Housing 41 is mounted through an opening in panel 49.

In accordance with the present invention, transport mechanism 40 isadapted to initially receive clean carrier 10 in the people-occupiedarea of the clean room. Carrier 10 is positioned on the transportmechanism with base 12 being secured in place on a moveable glider plateassembly 50 (shown in more detail in FIGS. 4, 5, 8, and 9). Plateassembly 50 is initially positioned in an aperture provided in the uppersurface of forward portion 42. When the transport mechanism isactivated, clean carrier 10 is opened, and glider plate 50 along withbase 12 drops away from cover 16 and is transported through housing 41and repositioned in an aperture located in rear portion 46. As base 12is separated from cover 16, cover 16 is lowered onto the top surface offorward portion 42 to overlay the aperture provided therein. Cover 16 issealed about the aperture on a contact seat disposed about the peripheryof the aperture. Air from the people-occupied environment is thusrestricted from entering the transport mechanism 40.

FIG. 3 shows cover 16 positioned in a sealed relationship on the uppersurface of forward portion 42. The transported semiconductor slicecassettes 52 are .[.shon.]. .Iadd.shown .Iaddend.positioned on rearportion 46 in preparation for loading the process machine.

FIG. 4 is a sectional side view of the transport mechanism of thepresent invention and illustrates the transitional movement of thesemiconductor slice cassettes 52 between forward portion 42 and rearportion 46. As shown in FIG. 4, a transport and gearing mechanism 54, tobe subsequently described, cooperates with glider plate 50 to move base12 within housing 41 in the direction of arrow 55 through an angle ofapproximately 200°. The semiconductor slice cassettes 52 are thustransported between forward portion 42 and rear portion 46 (shown as52'). As shown in FIG. 4 and described in greater detail in theco-pending patent application, carrier 10 is designed so that thesemiconductor slice cassettes are supported therein on base 12 at anangle of approximately 30° to said horizontal. Because it is desirableto present the semiconductor slices to the process machine in asubstantially horizontal orientation, gearing mechanism 54 is designedso that glider plate 50 is presented at rear portion 46 at an angle ofapproximately 30°. The semiconductor slice cassettes 52' are thussubstantially vertically oriented at rear portion 46, with the slicesbeing thus presented in the desired horizontal orientation.

FIG. 5 is a section front view of the transport mechanism of the presentinvention, taken from the forward portion 42, with the base 12 and slicecassettes 52 omitted for clarity of illustration. As shown in FIGS. 4and 5, the transport mechanism comprises a number of controls includinga drive motor 56 and a brake 58 coupled through belts 57 and 59 to driveand brake a drive shaft 60. A power supply 62, a circuit card rack 64and associated cooling fan 65 are provided proximate the bottom surfaceof housing 41, and are interconnected to provide power and control ofthe system. The transport mechanism also comprises a pair of belt driveassemblies 66, 68 positioned on and cooperating with the opposing sidesof glider plate 50 to effect movements of the glider plate 50 betweenforward portion 42 and rear portion 46.

Transport mechanism 40 also comprises a purge plate assembly 70, whichincludes glider plate 50, shown in greater detail in FIG. 6. As shown inFIG. 5, the area of housing 41 containing purge plate assembly 70 and aportion of belt drive assemblies 66 and 68 is encapsulated in astainless steel enclosure 72. Enclosure 72 thus isolates that portion ofhousing 41 from the particulate generating motors and fans located inthe lower portion of the machine. This isolation reduces the risk ofparticulate contamination being introduced to the semiconductor slicesas the semiconductor slice cassettes are being transported through thehousing. A flexible hose 74 is attached to enclosure 72 and communicateswith an orifice provided in the bottom surface of the enclosure 72. Hose74 extends downwardly through housing 41 to an exhaust fan 75 located onthe bottom surface of the housing.

The fan 75 is exhausted to an external area to thereby decrease thepressure within the interior of the housing 72. Generally, an areamaintained at a low contaminated level is pressurized with respect to anadjacent higher contamination level area. This pressure differenceminimizes the movement of particulate matter from the high to the lowcontamination areas. The pressure in the housing 72 is maintained at apressure lower than both the low contamination machine process area andthe high contamination people occupied area. In this manner, anycontaminating particles that enter the housing 72 are exhausted throughthe tube 74. The air flow induced by the pressure difference between theareas facilitates the isolation of the two areas and allows the base 12with the attached cassette carrier 52 to pass from one area to anotherwith minimum particulate transfer therebetween.

A second exhaust fan 76 is also provided on the bottom surface ofhousing 41 for exhausting the unenclosed portions of the transportmechanism. Because particles will also be generated by belt drives 66and 68 as a result of the contacting of their constituent belts andgears, a shroud 78 is disposed about the portion of each of said beltdrive assemblies situated within enclosure 72. Shroud 78 may alsoinclude a fitting (not shown) for attachment to a vacuum source so thatparticles trapped within the shroud can be evacuated.

FIG. 6 is an isolated front view of the drive belt assembly 66, it beingunderstood that drive belt assembly 68 is identical. A first shaft 80 isdisposed proximate the upper surface of the housing 41 and is securedthereto by an inverted yoke 70. A second shaft 81 is attached to gliderplate 50. Pulleys 82 and 83 are attached to shaft 80 in side-by-siderelationship. Pulley 83 is pinned to yoke 70 and does not rotate. Shaft80 also does not rotate. A third pulley 84 is attached to shaft 81. Apulley 85 is attached to drive shaft 60 for rotation therewith. Belt 86is disposed about pulleys 82 and 85 and a second belt 87 is disposedabout pulleys 83 and 84. Pulley 82 is pinned to the upper portion of anarm 88 which is rotatably connected about shaft 80 by bearings 89. Thus,rotation of pulley 82 causes rotation of the upper part of arm 88 aboutshaft 80. The lower part of arm 88 is connected through bearings 90 toshaft 81. Pivoting of arm 88 thus causes shaft 81 and glider plate 50 tomove about an arc centered at shaft 80. This causes the glider plate 50to move along the 200° arc between the two positions shown in FIG. 4.

Belt 87 is disposed around pulleys 83 and 84 and thus causes pulley 84to rotate as arm 88 swings about its arc. Rotation of pulley 84 causesglider plate 50 to rotate in order to maintain glider plate 50substantially horizontal during travel between its two locations.

FIG. 7 illustrates a belt tensioner device for use with the beltassemblies of FIG. 6. The tensioner is mounted on arm 88 and comprises ablock 92 having a spring 93 and a pair of rollers 94 and 95 provided ateither end thereof and positioned to contact and press against belt 87disposed about pulleys 83, 84. Block 92 is pivotable about a pivot 96mounted on arm 88. When incorporated into the transport mechanism of thepresent invention the tensioner acts to prevent the belt 87 fromslipping as pulleys 83, 84 on which it is disposed is rotated. Thetensioner device thus facilitates the positioning of glider plate 50 onrear portion 46 of the transport mechanism. Because the glider plate maynot approach rear portion 46 at the exact orientation so as to presentthe semiconductor slice cassettes in the aperture located in the uppersurface of portion 46, the tensioner allows the belt to give slightly,so that the glider plate 50 will properly orient itself proximate theaperture.

FIG. 8 is a sectional view of the purge plate assembly 70, includingglider plate 50 with a clean carrier 10 positioned thereon. As describedabove with respect to FIG. 1, guide slots 28 are provided on theunderside of clean carrier 10. Slots 28 are adapted to matingly engagewith orienting protrusions located on the upper surface of glider plate50 in order to secure carrier 10 to plate 50. Glider plate 50 isdesigned to correspond symmetrically to base 12 of carrier 10 andincludes apertures which communicate with filters 26 and orifice 30. Araised plastic strip extends along the forward edge of the glider plateso that when the carrier is positioned thereon, a small gap 100 will becreated between the bottom of the carrier and the top of the gliderplate.

Purge plate assembly 70 is shown in FIG. 8 and includes a fan 102attached to the lower surface of glider plate 50. Fan 102 is positionedto communicate through glider plate 50 with filters 26 located on thebase of the carrier and is provided within an encapsulated area 104.

A spacer 106 is positioned proximate the center of glider plate 50between the guider plate and encapsulated fan area 104. Spacer 106communicates with orifice 30 of carrier 10 through an orifice located inthe glider plate and extends therefrom downwardly through area 104 tocommunicate with a filter 108 mounted on the bottom of the area 104.

Fan 102 is designed to guard against the introduction of particulatecontamination from the people-occupied environment into the transportmechanism when the carrier 10 is opened at the commencement of thetransport operation. Thus when the carrier is positioned on glider plate50, a purging operation will be initiated in which fan 102 will beactivated to direct air into carrier 10 through filters 26 to therebycreate a positive pressure within the carrier. When the carrier isthereafter opened, any loose particles in the area surrounding thejunction of the cover and base of the carrier will be swept away fromthe carrier enclosure. As air is thus introduced through glider plate 50into filters 26, gap 100 between the bottom of the carrier and theglider plate will be under negative pressure to supply air to the fan102 through an orifice in the purge plate assembly 70. Any particulatecontamination in that area generated as a result of the contacting ofthe cooperating portions of the glider plate and the carrier will beprevented from entering the clean carrier by the filters 26. Inaddition, the slight positive pressure build-up within carrier 10 willforce air down latch tube 24, which air will then travel down the centerof the tube away from the latching mechanism contained therein andthrough the glider plate and spacer and be directed through filter 108.The filtering of this air thus further reduces the risk of particulatecontamination being introduced into the transport mechanism.

FIG. 9 illustrates the operation of the belt drive assemblies 66 and 68to cause glider plate 50 to swing downwardly about a 200° arc and bepivoted toward rear portion 46 at an angle of approximately 30°. Shroud78 encompasses the pulley and belt structure shown in FIG. 6. As shownin FIG. 9 and described above with reference to earlier FIGURES, thecombination of the belts, pulleys and shafts of the invention areoperative to cause glider plate 50 to move in a 200° arc in thedirection to arrow 110. Glider plate 50 is thus moved to position 50'.Upon actuation of a switch (not shown) by the operator, motor 56 isactuated by control signals generated from electronic circuitry in cardrack 64. The glider plate 50 is then moved to the desired position withthe process area, where the brake causes the plate 50 to be stopped. Thesemiconductor slices are presented at the desired angle for furtherprocessing. Actuation of the switch by the operator then causes theplate 50 to be moved to the original position for reloading of thecarrier with new slices or returning processed slices.

In summary, a transport mechanism has been described for transferringsemiconductor cassettes and slices between a portable carrying unit inthe people-occupied area of a clean room and a process machine areaaerodynamically isolated from people without exposing the slices toparticulate contamination or introducing particulate contamination tothe process machine area.

Although the preferred embodiment has been described in detail, itshould be understood that various changes, substitutions, andalterations can be made therein without departing from the spirit andscope of the invention as defined by the appended claims.

What is claimed is:
 1. An apparatus for transporting semiconductor slicecassettes in a portable carrier between a high contamination area and alow contamination area, said portable carrier having a base carrying theslice cassettes and a cover removably attached to the base, comprising:ahousing having a forward portion disposed in the high contamination areaand a rear portion positioned in the low contamination area said rearportion isolated from said forward portion by a barrier wall; saidhousing having an interior portion in communication with the highcontamination area through a first access opening in said forwardportion and with the low contamination area through a second accessopening in said area portion; the cover of the portable carrier beingsealingly receivable over the first access opening in isolate theinterior portion of the housing from the high cotamination area; meansfor creating a positive pressure within the portable carrier prior toremoving of the cover of the portable carrier from the base; means forcreating a negative pressure within the interior of said housingrelative to both the high and low contamination areas; support meansdisposed within said housing for receiving the base of the portablecarrier and operable to be alternately disposed proximate said firstaccess opening and said second access opening to move the base of theportable carrier and the slice cassettes therebetween; and motive forcemeans disposed within said housing for causing said support means and atleast a portion of the portable carrier to be moved between said firstaccess opening and said second access opening.
 2. The apparatus of claim1 and further comprising arm means pivotally connected between saidsupport means and a pivot point within said housing for moving thecarrier about an arc between said first and second access openings. 3.The apparatus of claim 1 wherein said motive force means comprises:amotor; a drive shaft connected to said motor for rotation thereof; anddrive belt assembly means positioned on opposing sides of said supportmeans for cooperating with said drive shaft to cause vertical andpivotable movement of said support means.
 4. The apparatus of claim 3wherein said drive belt assembly comprises:a first shaft secured withinsaid housing; a second shaft attached to said support means; first andsecond pulleys attached to said first shaft in side-by-siderelationships; a third pulley attached to said second shaft; a fourthpulley attached to said drive shaft for rotation therewith; a first beltdisposed about said first and fourth pulley; and a second belt disposedabout said second and third pulley.
 5. The apparatus of claim 4 andfurther comprising an enclosure positioned to surround said supportmeans and a portion of said belt drive assemblies containing said secondbelt, said second and third pulleys and the portion of said second shaftsupporting said second belt.
 6. The apparatus of claim 4 and furthercomprising a belt tensioner to prevent said belts from slipping off saidpulleys as the pulleys are rotated.
 7. The apparatus of claim 5 andfurther comprising a shroud disposed about said portions of said beltdrive assemblies.
 8. The apparatus of claim 5 wherein said means forcreating a negative pressure within the interior of said housingrelative to both the high and low contamination areas comprises anexhaust fan positioned on the bottom inner surface of said housing. 9.The apparatus of claim 8 wherein an aperture is provided at the bottomof said enclosure and extends to the exterior thereof for attachmentthrough a hose to said exhaust fan.
 10. The apparatus of claim 8 andfurther comprising a second exhaust fan positioned on the bottom innersurface of said housing for evacuating particulate contaminationtherefrom.
 11. An apparatus for transporting semiconductor slicecassettes in a portable carrier having a detachable cover and basebetween a high contamination area and a low contamination areacomprising:a housing having a forward portion disposed in the highcontamination area and a rear portion positioned in the lowcontamination area and isolated from said forward portion behind an airdrop panel disposed between the high and low contamination areas; saidhousing having its interior in communication with the high contaminationarea through a first access opening in said forward position and withthe low contamination area through a second access opening in said rearportion; said first access opening mating with the cover of the portablecarrier to allow the base to pass therethrough and support the cover toseal the interior of the housing from the high contamination area;support means within said housing for cooperating with the base of thecarrier to provide support therefor and adapted to be alternatelydisposed proximate said first access opening and said second accessopening, said support means having: a guider plate having meanspositioned thereon to matingly engage with the base of the carrier; anarm connected to said plate and pivotable about an arc between saidforward and rear portions; means for creating a positive pressure withinthe portable carrier prior to removing of the cover of the portablecarrier from the base; means for creating a negative pressure within theinterior of said housing relative to both the high and low contaminationareas; motive force means disposed within said housing for causing saidarm to pivot said support means and the carrier base mounted thereonbetween said forward portion and said rear portion.
 12. The apparatus ofclaim 11 wherein said means for creating a positive pressure within theportable carrier comprises a fan positioned below said guider plate andattached thereto, said fan encapsulated in a sealed enclosure fordirecting air towards the base of the portable carrier and to theinterior thereof.
 13. The apparatus of claim 12 wherein said supportmeans further comprises a tubular spacer positioned between said gliderplate and said fan enclosure at the center of said glider plate andextending from said glider plate through said fan enclosure tocommunicate with a breathing orifice on the base of the portablecarrier.
 14. The apparatus of claim 11 wherein said glider plate isconstructed so as to conform substantially to the base of the carrierand includes apertures which communicate with the breathing orifices onthe portable carrier and with an orifice provided at the terminal end ofthe latch tube of the carrier.
 15. The apparatus of claim 12 wherein aplastic strip is provided along the forward edges of said glider plateso that when the base is secured to said glider plate, a gap is formedbetween the bottom surface of the carrier and the upper surface of theglider plate.
 16. The apparatus of claim 13 wherein said fan is adaptedto direct air into said carrier through said glider plate and thefilters of said carrier to create a positive pressure within saidcarrier and to also create a negative pressure within the gap betweensaid glider plate and said carrier to prevent introduction ofparticulate contamination into said carrier when said carrier is opened..Iadd.
 17. An interface between first and second containers used forsemiconductor wafer manufacture, comprising:(a) a first door for sealingthe first container; (b) a second door for sealing the second container;(c) said first and second doors each having a mating outer surface sothat substantially all contamination which has accumulated on exteriorsurfaces of the doors when the containers are separated will be trappedwhen the containers are positioned together; and (d) further includingan elevator coupled to said doors for transporting said doors into saidcontainers as a single unit while said doors are coupled together attheir mating outer surfaces..Iaddend. .Iadd.
 18. An interface betweenfirst and second containers, comprising:(a) a first door forindependently sealing the first container; (b) a second door forindependently sealing the second container; (c) said first and seconddoors each having a mating outer surface of substantially equal exteriordimensions so that substantially all contamination which has accumulatedon the exterior surface of the doors when the containers are separatedwill be trapped when the containers are positioned together; and (d) anelevator coupled to said doors for transporting said doors into saidcontainers as a single unit while said doors are coupled together attheir mating outer surfaces..Iaddend. .Iadd.19. The interface of claim18 wherein the first container is isolated from ambient..Iaddend..Iadd.20. The interface of claim 18 wherein the first container preventscontamination..Iaddend. .Iadd.21. The interface of claim 18 wherein thefirst container prevents contamination from entering the inside of thecontainer..Iaddend. .Iadd.22. The interface of claim 18 wherein theinterface prevents contamination..Iaddend. .Iadd.23. The interface ofclaim 18 wherein the interface prevents contamination of the inside ofthe first container..Iaddend. .Iadd.24. The interface of claim 18wherein the interface prevents contamination of the inside of the secondcontainer..Iaddend. .Iadd.25. The interface of claim 18 wherein thefirst container is maintained at atmospheric pressure..Iaddend..Iadd.26. The interface of claim 18 wherein the first container ismaintained at ambient pressure..Iaddend. .Iadd.27. The interface ofclaim 18 wherein ambient contains particulate contamination..Iaddend..Iadd.28. The interface of claim 18 wherein wafers are stored in thefirst container..Iaddend. .Iadd.29. An semiconductor wafer manufacturingsystem, comprising:(a) a clean carrier; (b) a base controllably attachedto the clean carrier for sealing the clean carrier; (c) a transportunit; (d) a glider plate attached to the transport unit; (e) the baseand the glider plate each having a mating outer surface of substantiallyequal exterior dimensions so that substantially all contamination whichhas accumulated on the exterior surface of the doors when the carrierand transport unit are separated will be trapped when the base and theglider plate are positioned together; and (f) a transport mechanismcoupled to the glider plate and base for transporting the base and theglider plate into the clean carrier and the transport unit as a singleunit while said doors are coupled together at their mating outersurfaces..Iaddend. .Iadd.30. A method of interfacing a wafer carrier toa housing, comprising the steps of:(a) providing a door for the wafercarrier; (b) providing a door for an opening in the housing; (c) placingthe wafer carrier so that its door mates with the housing door; and (d)trapping particulates located between the two mated doors..Iaddend..Iadd.31. The method of claim 30 further comprising: (a) transportingthe two mated doors as a unit into the interior of the housing..Iaddend..Iadd.32. The method of claim 30 further comprising: (a) using the wafercarrier to cover the housing opening to prevent particulates fromentering the housing..Iaddend.